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Journal of Materials Science

, Volume 30, Issue 24, pp 6223–6234 | Cite as

An in situ hot stage transmission electron microscopy study of the decomposition of Fe-C austenites

  • M. Onink
  • F. D. Tichelaar
  • C. M. Brakman
  • E. J. Mittemeijer
  • S. van der Zwaag
Article

Abstract

Hot stage transmission electron microscopy is applied to determine the growth mechanism during decomposition of austenite in hypo-eutectoid Fe-C austenites. The austenite-ferrite interface is mostly curved and moves sluggishly with periods of acceleration and deceleration. In some cases the interface is nearly straight and effectively immobile. Then, migration takes place by means of ledges which displace parallel to the immobile straight interface. The ledges migrate at a rate equal to the migration rate predicted for diffusion controlled migration. The highest migration rates observed for the curved interface are nearly equal to that calculated for diffusion controlled growth. The observed succession of periods of acceleration and deceleration for the curved interface is not predicted in the common theories for interface mobility during phase transformation. Detailed examination of region around the interface indicate that stress build up and stress relaxation are responsible for the deceleration and acceleration respectively. The stresses are due to the volume misfit between the ferrite formed and the parent austenite.

Keywords

Ferrite Austenite Stress Relaxation Electron Microscopy Study Migration Rate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • M. Onink
    • 1
  • F. D. Tichelaar
    • 1
  • C. M. Brakman
    • 1
  • E. J. Mittemeijer
    • 1
  • S. van der Zwaag
    • 1
  1. 1.Laboratory for Materials ScienceDelft University of TechnologyAL DelftThe Netherlands

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